New strength to planck’s length choice

The calculation of the total mass of a spacetime in which an observer-independent scale of length exist is possible through the use of Heisenberg Uncertainty Principle. In the following paragraphs we show that such a spacetime has a total mass equal to the mass of our Universe observed by the WMAP Nasa spacecraft if the cited observer-independent scale of length is determined by the Plank's length lp. This result gives new strength to fundamental theories that make use of lp as a length with a "special role", like the various string theories